LAG3 Binding Peptides

ABSTRACT

This disclosure provides peptides which bind to LAG3 and can be used to block the interaction of LAG 3 with other molecules such as MHC-II, FGL1, and α-synuclein. These peptides can be used for various therapeutic purposes, such as inhibiting the progression of a hyperproliferative disorder, including cancer, or inhibiting the progression of a synucleinopathy, inhibiting the progression of sepsis, inhibiting the progression of an infectious disease, and enhancing a response to a vaccine.

This application incorporates by reference the contents of a 2.37 kb text filed created on May 20, 2020 and named “USsequencelisting.txt,” which is the sequence listing for this application.

Each scientific reference, patent, and published patent application cited in this disclosure is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This disclosure relates generally to immunomodulatory peptides.

BACKGROUND

Lymphocyte activation gene 3 (LAG3, also known as LAG-3, LAG 3, Lag3, CD223, FDC protein) is a member of the immunoglobulin superfamily of receptors.

LAG3 is expressed on immune cells (activated T cells, Huard et al., 1994; natural killer cells, Triebel et al., 1990; B cells, Kisielow et al., 2005; plasmacytoid dendritic cells, Workman et al., 2009), where it binds to MHC class II (MHC-II) and serves as an immune checkpoint receptor. LAG3 also binds to fibrinogen-like protein (FGL1), and disrupting this binding can potentiate anti-tumor immunity (Wang et al., 2019). There is a continuing need for useful modulators of immune checkpoint pathways.

LAG3 is also expressed on neurons, where it serves as a receptor for the α-synuclein aggregates characteristic of synucleinopathies (Mao et al., 2016). Synucleinopathies are disorders characterized by the abnormal accumulation of aggregates of α-synuclein protein in neurons, nerve fibers, or glial cells. Synucleinopathies include idiopathic and inherited forms of Parkinson's disease (PD); Diffuse Lewy Body (DLB) disease, also known as Dementia with Lewy Bodies or Lewy body dementia; incidental Lewy body disease; Lewy body variant of Alzheimer's disease (LBV); Combined Alzheimer's and Parkinson disease (CAPD); pure autonomic failure (PAF); multiple system atrophy (MSA), such as olivopontocerebellar atrophy, striatonigral degeneration, and Shy-Drager Syndrome; pantothenate kinase-associated neurodegeneration; Down's Syndrome; Gaucher disease-related synucleinopathies; and neurodegeneration with brain iron accumulation. There is a continuing need for therapeutic agents for treating or managing symptoms of synucleinopathies.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A and FIG. 1B are graphs showing the results of LAG3 blockage functional inhibition assays described in Example 2.

FIG. 2A, FIG. 2B, FIG. 2C, and FIG. 2D are graphs showing the results of four independent homogeneous time-resolved fluorescence (HTRF) assays for peptide LAG3-11. Reference Ab-LAG3 is an anti-LAG3 antibody. OVA, the ovalbumin (OVA) peptide (ISQAVHAAHAEINEAGR, SEQ ID NO:8). “HTRF ratio” is the emission at 665 nm (Acceptor)/ emission at 620 nm (Donor) multiplied by a factor or 10⁴.

FIG. 3 is a graph showing the results of an HTRF assay for peptide LAG3-11. Anti-LAG-3 GMP-A092 is an anti-LAG3 antibody.

FIG. 4 is a graph showing the results of an HTRF assay for peptide LAG3-42.

FIG. 5 is a graph showing the results of an HTRF assay for peptide LAG3-48.

FIG. 6 is a graph showing the results of an HTRF assay for peptide LAG3-51.

FIG. 7 is a graph showing the results of an HTRF assay for peptide LAG3-54.

FIG. 8 is a graph showing the results of an HTRF assay for peptide LAG3-56.

FIG. 9 is a graph showing the results of an HTRF assay for peptide LAG3-60.

FIG. 10 is a graph showing the results of a peripheral blood mononuclear cell (PBMC) assay.

FIG. 11 is a graph showing the results of a Human LAG3/FGL1 TR-FRET Binding Assay.

DETAILED DESCRIPTION

This disclosure provides peptides that bind to LAG3 and can be used to block its interaction with other molecules such as MHC-II, FGL1, and α-synuclein.

TABLE 1 SEQ ID peptide amino acid sequence NO: LAG3-11 SAPWEPLHWPEDWWQGTGEW 1 LAG3-42 DWNFQQWDWKKHNHLDSHVV 2 LAG3-48 FYSPNHEEYHDWNVDSSVNE 3 LAG3-51 KVWQVPQDTQHWLSPNFYSV 4 LAG3-54 ACGPGSFGDCGGG 5 LAG3-56 HIQNWSYWLNQDMMNQQVWKS 6 LAG3-60 HESGSVPHPWQFFTHYVS 7

In some embodiments, a disclosed peptide is modified using chemical or recombinant methods to enhance its stability or other pharmacokinetic properties. See, e.g., US 2017/0020956. Modifications include, but are not limited to, replacement of one or more L-amino acid with its corresponding D-form, acetylation on a C- and/or N-terminal residue, amidation on a C- and/or N-terminal residue, cyclization, esterification, glycosylation, acylation, attachment of myristic or palmitic acid, addition of an N-terminal glycine, addition of lipophilic moieties such as long fatty acid chains, and PEGylation.

Peptides can be made by any method known in the art, including synthetic methods, recombinant methods, or both. Synthetic methods include solid-phase and solution methods, and may include the use of protective groups. See, e.g., Bodanszky et al. (1976), McOmie (1973), Merrifield (1963), Neurath et al. (1976), Stuart & Young (1984).

Recombinant production of peptides can be carried out using any nucleotide sequence(s) encoding the peptides in any suitable expression system. Nucleic acid molecules encoding one or more of the disclosed peptides can be incorporated into an expression cassette that includes control elements operably linked to the coding sequences. Control elements include, but are not limited to, initiators, promoters (including inducible, repressible, and constitutive promoters), enhancers, and polyadenylation signals. Signal sequences can be included. The expression cassette can be provided in a vector that can be introduced into an appropriate host cell for production of the peptide(s). Methods of constructing expression cassettes and expression vectors are well known. Expression vectors can include one or more expression cassettes encoding one or more peptides comprising, consisting essentially or, or consisting of any of SEQ ID NOS:1-7.

In some embodiments, one or more peptides are expressed as a component of a fusion protein. Other components of the fusion protein can be, for example, a cytokine or an engineered T cell receptor (TCR). A fusion protein can comprise one or more linkers between its components. In some embodiments, a linker between a peptide and another component of the fusion protein can comprise a proteolytic cleavage site to release the peptide after expression of the fusion protein. See, e.g., US 2016/0138066; US 2018/0135060; US 2014/0343251; US 2012/0142891; Rodriguez et al., 2014.

In some embodiments, a component of a fusion protein is a moiety, such as albumin or transthyretin, which can enhance the plasma half-life of the peptide. In other embodiments, a peptide or a modified version of a peptide is conjugated to the moiety. Methods of preparing such conjugates are well known in the art (e.g., Penchala et al., 2015; Kontermann, 2016; Zorzi et al., 2017).

In some embodiments, a component of a fusion protein is a partner molecule, such as a peptide or protein such as an antibody intended to increase the half-life of a peptide or modified peptide in vivo and/or to provide specific delivery to a target tissue or cell. Alternatively, a peptide or modified version thereof can be conjugated to the partner molecule. Conjugation may be direct or can be via a linker. In some of these embodiments, a peptide or a modified version thereof can be altered to substitute one or more amino acids with amino acids used to attach partner molecules, such as lysine, or by N-terminal extension of the peptide with, e.g., 1, 2, 3, or 4 glycine spacer molecules.

This disclosure also provides CAR-T cells that express one or more of the disclosed peptides. Methods of preparing CAR-T cells are disclosed, for example, in U.S. Pat. Nos. 9,328,156; 9,845,362; and 9,101,584.

This disclosure also provides oncolytic viruses containing a nucleic acid molecule encoding one or more of the disclosed peptides. See US 2017/0157188; Lawler et al., 2017; US 2015/0250837. Oncolytic viruses include, but are not limited to, reovirus, Seneca Valley virus, vesicular stomatitis virus, Newcastle disease virus, herpes simplex virus, morbillivirus virus, retrovirus, influenza virus, Sindbis virus, poxvirus, and adenovirus.

Examples of oncolytic reovirus include REOLYSIN® (pelareorep) and reoviruses disclosed in US 2017/0049829.

Examples of oncolytic Seneca Valley virus include NTX-101 (Rudin et al., 2011).

Examples of oncolytic vesicular stomatitis virus are disclosed in Stojdl et al., 2000; and Stojdl et al., 2003.

Examples of oncolytic Newcastle disease virus include 73-T PV701 and HDV-HUJ strains (see also Phuangsab et al., 2001; Lorence et al., 2007; and Freeman et al., 2006).

Examples of oncolytic herpes simplex virus include NV1020 (Geevarghese et al., 2010) and T-VEC (Andtbacka et al., 2013).

Examples of oncolytic morbillivirus virus include oncolytic measles viruses such as MV-Edm (McDonald et al., 2006) and HMWMAA (Kaufmann et al., 2013).

Examples of oncolytic retrovirus are disclosed in Lu et al., 2012.

Examples of oncolytic influenza virus are disclosed, for example, in US 2018/0057594.

Examples of oncolytic Sindbis virus are disclosed, for example, in Lundstrom, 2017.

Examples of oncolytic poxvirus are disclosed, for example, in Chan & McFadden, 2014.

Examples of oncolytic adenovirus include ONYX-015 (Khuri et al., 2000) and H101 or Oncorine (Liang, 2018).

Therapeutic Uses

The peptides and modified versions thereof disclosed herein have a number of therapeutic applications, including treating hyperproliferative disorders (e.g., cancer). “Treat,” as used herein, includes reducing or inhibiting the progression of one or more symptoms of the condition for which a peptide or modified version thereof is administered. The peptides and modified versions thereof may also be useful for reducing one or more symptoms of or for treating synucleopathies, infectious diseases, and sepsis and for enhancing a response to vaccination.

“Administer” as used herein includes administration of a disclosed peptide or modified version thereof itself as well as administration by various vehicles described below.

In some embodiments, one or more of the disclosed peptides and/or modified versions thereof, are directly administered. In some of these embodiments, a peptide carrier system is used. A number of peptide carrier systems are known in the art, including microparticles, polymeric nanoparticles, liposomes, solid lipid nanoparticles, hydrophilic mucoadhesive polymers, thiolated polymers, polymer matrices, nanoemulsions, and hydrogels. See Patel et al. (2014), Bruno et al. (2013), Feridooni et al. (2016). Any suitable system can be used.

In some embodiments, an engineered T cell that expresses and secretes one or more disclosed peptides can be used to deliver LAG3 inhibition at the site of engagement of the T cell receptor with an antigen. The T cell-based therapy can be, for example, a CAR-T cell that expresses one or more of the disclosed peptides. Either inducible or constitutive expression can be used.

In some embodiments, an oncolytic virus can be used to deliver one or more of the disclosed peptides. Either inducible or constitutive expression can be used.

In other embodiments one or more of the disclosed peptides are delivered using one or more nucleic acids encoding the peptide(s) (e.g., DNA, cDNA, PNA, RNA or a combination thereof); see, e.g., US 2017/0165335. Nucleic acids encoding one or more peptides can be delivered using a variety of delivery systems known in the art. Nucleic acid delivery systems include, but are not limited to, gene-gun; cationic lipids and cationic polymers; encapsulation in liposomes, microparticles, or microcapsules; electroporation; virus-based, and bacterial-based delivery systems. Virus-based systems include, but are not limited to, modified viruses such as adenovirus, adeno-associated virus, herpes virus, retroviruses, vaccinia virus, or hybrid viruses containing elements of one or more viruses. US 2002/0111323 describes use of “naked DNA,” i.e., a “non-infectious, non-immunogenic, non-integrating DNA sequence,” free from “transfection-facilitating proteins, viral particles, liposomal formulations, charged lipids and calcium phosphate precipitating agents,” to administer a peptide. Bacterial-based delivery systems are disclosed, e.g., in Van Dessel et al. (2015) and Yang et al. (2007).

In some embodiments, a peptide is administered via an RNA molecule encoding the peptide. In some embodiments, the RNA molecule is encapsulated in a nanoparticle. In some embodiments, the nanoparticle comprises a cationic polymer (e.g., poly-L-lysine, polyamidoamine, polyethyleneimine, chitosan, poly(β-amino esters). In some embodiments, the nanoparticle comprises a cationic lipid or an ionizable lipid. In some embodiments, the RNA molecule is conjugated to a bioactive ligand (e.g., N-acetylgalactosamine (GalNAc), cholesterol, vitamin E, antibodies, cell-penetrating peptides). See, e.g., Akinc et al. (2008), Akinc et al. (2009), Anderson et al. (2003), Behr (1997), Boussif et al. (1995), Chen et al. (2012), Dahlman et al. (2014), Desigaux et al. (2007), Dong et al. (2014), Dosta et al. (2015), Fenton et al. (2016), Guo et al. (2012), Howard et al. (2006), Kaczmarek et al. (2016), Kanasty et al. (2013), Kauffman et al. (2015), Kozielski et al. (2013), Leus et al. (2014), Lorenz et al. (2004), Love et al. (2010), Lynn & Langer (2000), Moschos et al. (2007), Nair et al. (2014), Nishina et al. (2008), Pack et al. (2005), Rehman et al. (2013), Schroeder et al. (2010), Tsutsumi et al. (2007), Tzeng et al. (2012), Won et al. (2009), Xia et al. (2009), Yu et al. (2016).

In some embodiments, an RNA molecule can be modified to reduce its chances of degradation or recognition by the immune system. The ribose sugar, the phosphate linkage, and/or individual bases can be modified. See, e.g., Behlke (2008), Bramsen (2009), Chiu (2003), Judge & MacLachlan (2008), Kauffman (2016), Li (2016), Morrissey (2005), Prakash (2005), Pratt & MacRae (2009), Sahin (2014), Soutschek (2004), Wittrup & Lieberman (2015). In some embodiments, the modification is one or more of a ribo-difluorotoluyl nucleotide, a 4′-thio modified RNA, a boranophosphate linkage, a phosphorothioate linkage, a 2′-O-methyl (2′-OMe) sugar substitution, a 2′-fluoro (2′-F), a 2′-O-methoxyethyl (2′-MOE) sugar substitution, a locked nucleic acid (LNA), and an L-RNA.

In some embodiments, administration is carried out in conjunction with one or more other therapies. “In conjunction with” includes administration together with, before, or after administration of the one or more other therapies.

Pharmaceutical Compositions, Routes of Administration, and Devices

One or more peptides, modified peptides, nucleic acid molecules, CAR-T cells, and/or oncolytic viruses, as discussed above, are typically administered in a pharmaceutical composition comprising a pharmaceutically acceptable vehicle. The “pharmaceutically acceptable vehicle” may comprise one or more substances which do not affect the biological activity of the peptides or modified versions thereof and, when administered to a patient, does not cause an adverse reaction. Pharmaceutical compositions may be liquid or may be lyophilized. Lyophilized compositions may be provided in a kit with a suitable liquid, typically water for injection (WFI) for use in reconstituting the composition. Other suitable forms of pharmaceutical compositions include suspensions, emulsions, and tablets.

Pharmaceutical compositions can be administered by any suitable route, including, but not limited to, intravenous, intramuscular, intradermal, intraperitoneal, subcutaneous, epidural, intratumoral, transdermal (e.g., US 2017/0281672), mucosal (e.g., intranasal or oral), pulmonary, and topical (e.g., US 2017/0274010) routes. See, e.g., US 2017/0101474.

Administration can be systemic or local. In addition to local infusions and injections, implants can be used to achieve a local administration. Examples of suitable materials include, but are not limited to, sialastic membranes, polymers, fibrous matrices, and collagen matrices.

Topical administration can be by way of a cream, ointment, lotion, transdermal patch (such as a microneedle patch), or other suitable forms well known in the art.

Administration can also be by controlled release, for example, using a microneedle patch, pump and/or suitable polymeric materials. Examples of suitable materials include, but are not limited to, poly(2-hydroxy ethyl methacrylate), poly(methyl methacrylate), poly(acrylic acid), poly(ethylene-co-vinyl acetate), poly(methacrylic acid), polyglycolides (PLG), polyanhydrides, poly(N-vinyl pyrrolidone), poly(vinyl alcohol), polyacrylamide, poly(ethylene glycol), polylactides (PLA), poly(lactide-co-glycolides) (PLGA), and polyorthoesters.

Devices comprising any of the peptides, modified peptides, nucleic acid molecules, CAR-T cells, and/or oncolytic viruses described above include, but are not limited to, syringes, pumps, transdermal patches, spray devices, vaginal rings, and pessaries.

Treatment of Hyperproliferative Disorders, Including Cancer

In some embodiments, one or more of the peptides, modified peptides, nucleic acid molecules, CAR-T cells, and/or oncolytic viruses described above are administered to a patient to inhibit the progression of a hyperproliferative disorder, including cancer. Such inhibition may include, for example, reducing proliferation of neoplastic or pre-neoplastic cells; destroying neoplastic or pre-neoplastic cells; and inhibiting metastasis or decreasing the size of a tumor.

Examples of cancers include, but are not limited to, melanoma (including cutaneous or intraocular malignant melanoma), renal cancer, prostate cancer, breast cancer, colon cancer, lung cancer, bone cancer, pancreatic cancer, skin cancer, cancer of the head or neck, uterine cancer, ovarian cancer, rectal cancer, cancer of the anal region, stomach cancer, testicular cancer, carcinoma of the fallopian tubes, carcinoma of the endometrium, carcinoma of the cervix, carcinoma of the vagina, carcinoma of the vulva, Hodgkin's Disease, non-Hodgkin's lymphoma, cancer of the esophagus, cancer of the small intestine, cancer of the endocrine system, cancer of the thyroid gland, cancer of the parathyroid gland, cancer of the adrenal gland, sarcoma of soft tissue, cancer of the urethra, cancer of the penis, chronic or acute leukemias including acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, chronic lymphocytic leukemia, lymphocytic lymphoma, cancer of the bladder, cancer of the kidney or ureter, carcinoma of the renal pelvis, neoplasm of the central nervous system (CNS), primary CNS lymphoma, tumor angiogenesis, spinal axis tumor, brain stem glioma, pituitary adenoma, Kaposi's sarcoma, epidermoid cancer, squamous cell cancer, and T-cell lymphoma.

Combination Cancer Therapies

In some embodiments, one or more of the peptides, modified peptides, nucleic acid molecules, CAR-T cells, and/or oncolytic viruses described above are administered in conjunction with one or more other cancer therapies or immunotherapies, such as those described below.

In some embodiments, the second therapy comprises a second agent that reduces or blocks the activity of PD-1 (e.g., nivolumab, pembrolizumab, durvalumab) or CTLA-4 (e.g., ipilimumab, tremelimumab).

In some embodiments, the second therapy comprises an agent that reduces or blocks the activity of PD-L1 (e.g., atezolizumab).

In some embodiments, the second therapy comprises an agent that reduces or blocks the activity of LAG3 or other inhibitory checkpoint molecules and/or molecules that suppress the immune system. These molecules include, but are not limited to:

-   -   1. V-domain Immunoglobulin Suppressor of T cell Activation         (VISTA, also known as c10orf54, PD-1H, DD1α, Gi24, Dies1, and         SISP1; see US 2017/0334990, US 2017/0112929, Gao et al., 2017,         Wang et al., 2011; Liu et al., 2015);     -   2. T-cell Immunoglobulin domain and Mucin domain 3 (TIM-3; see         US 2017/0198041, US 2017/0029485, US 2014/0348842, Sakuishi et         al., 2010);     -   3. killer immunoglobulin-like receptors (KIRs; see US         2015/0290316);     -   4. agents that inhibit indoleamine (2,3)-dioxygenase (IDO; see         Mellemgaard et al., 2017);     -   5. B and T Lymphocyte Attenuator (BTLA; see US 2016/09222114);         and     -   6. A2A adenosine receptor (A2AR; see Beavis et al., 2015; US         2013/0267515; US 2017/0166878; Leone et al., 2015;         Mediavilla-Varela et al., 2017; Young et al., 2016).

Agents that reduce or block the activity of LAG3 include, but are not limited to, BMS-986016, IMP321, and GSK2831781 (He et al., 2016).

Agents that reduce or block the activity of VISTA include, but are not limited to, small molecules, such as CA-170, and antibodies (e.g., Le Mercier et al., 2014).

Agents that reduce or block the activity of TIM-3 include, but are not limited to, antibodies such as MBG453 and TSR-022; see Dempke et al., 2017.

Agents that reduce or block the activity of KIRs include, but are not limited to, monoclonal antibodies such as IPH2101 and Lirilumab (BMS-986015, formerly IPH2102); see Benson & Caligiuri, 2014.

Agents that reduce or block the activity of IDO include, but are not limited to, epacadostat and agents disclosed in US 2017/0037125.

Agents that reduce or block the activity of BTLA include, but are not limited to, peptides (e.g., Spodzieja et al., 2017).

Agents that reduce or block the activity of A2AR include, but are not limited to, small molecules such as CPI-444 and vipadenant.

In some embodiments, the second therapy comprises a cytokine (e.g., interleukin 7).

In some embodiments, the second therapy comprises an agonist of a stimulatory checkpoint molecule. These molecules include, but are not limited to:

-   -   1. CD40;     -   2. OX40;     -   3. glucocorticoid-induced tumor necrosis factor-related protein         (GITR); and     -   4. Inducible T-cell COStimulator (ICOS).

Agonists of CD40 include, but are not limited to, CD40 agonist monoclonal antibodies such as cp-870,893, ChiLob7/4, dacetuzumab, and lucatumumab. See, e.g., Vonderheide et al., 2007; Khubchandani et al., 2009; Johnson et al., 2010; Bensinger et al., 2012; Vonderheide and Glennie, 2013; Johnson et al., 2015.

Agonists of OX40 include, but are not limited to, OX40 agonist antibodies such as MOXR0916, MED16469, MED10562, PF-045618600, GSK3174998, and INCCAGN01949, and OX40L-Fc fusion proteins, such as MEDI6383. See, e.g., Huseni et al., 2014; Linch et al., 2015; Messenheimer et al., 2017. See also Shrimali et al., 2017.

Agonists of GITR include, but are not limited to, MEDI1873. See, e.g., Schaer et al., 2012; Tigue et al., 2017.

Agonists of ICOS include, but are not limited to, ICOS agonist antibodies JTX-2011 and GSK3359609. See, e.g., Harvey et al., 2015; Michaelson et al., 2016.

In other embodiments, the second therapy comprises a 4-1BB agonist (Shindo et al., 2015), such as urelumab; a 4-1BB antagonist (see US 2017/0174773); an inhibitor of anaplastic lymphoma kinase (ALK; Wang et al., 2014; US 2017/0274074), such as crizotinib, ceritinib, alectinib, PF-06463922, NVP-TAE684, AP26113, TSR-011, X-396, CEP-37440, RXDX-101; an inhibitor of histone deacetylase (HDAC; see US 2017/0327582); a VEGFR inhibitor, such as axitinib, sunitinib, sorafenib, tivozanib, bevacizumab; and/or an anti-CD27 antibody, such as varlilumab.

In some embodiments, the second therapy comprises a cancer vaccine (e.g., Duraiswamy et al., 2013). A “cancer vaccine” is an immunogenic composition intended to elicit an immune response against a particular antigen in the individual to which the cancer vaccine is administered. A cancer vaccine typically contains a tumor antigen which is able to induce or stimulate an immune response against the tumor antigen. A “tumor antigen” is an antigen that is present on the surface of a target tumor. A tumor antigen may be a molecule which is not expressed by a non-tumor cell or may be, for example, an altered version of a molecule expressed by a non-tumor cell (e.g., a protein that is misfolded, truncated, or otherwise mutated).

In some embodiments, the second therapy comprises a chimeric antigen receptor (CAR) T cell therapy. See, e.g., John et al., 2013; Chong et al., 2016.

In some embodiments, one or more of the peptides, modified peptides, nucleic acid molecules, CAR-T cells, and/or oncolytic viruses described above are administered in conjunction with a CAR-T cell cancer therapy to increase the efficacy of the CAR-T cell cancer therapy.

In some embodiments, one or more of the peptides, modified peptides, nucleic acid molecules, CAR-T cells, and/or oncolytic viruses described above are administered in conjunction with an oncolytic virus as disclosed, for example, in US 2017/0143780. Non-limiting examples of oncolytic viruses are described above.

Additional Therapeutic Uses

Synucleinopathies

In some embodiments, one or more of the peptides, modified peptides, nucleic acid molecules, CAR-T cells, and/or oncolytic viruses described above may be useful to reduce a symptom of a synucleinopathy, either alone or in combination with other therapeutic interventions such as L-DOPA, dopamine agonists (e.g., ropinirole, pramipexole), dopamine reuptake inhibitors (e.g., amantadine), and cholinesterase inhibitors (e.g., donepezil, rivastigmine, galantamine). Examples of synucleinopathies include idiopathic and inherited forms of Parkinson's disease (PD); Diffuse Lewy Body (DLB) disease, also known as Dementia with Lewy Bodies or Lewy body dementia; incidental Lewy body disease; Lewy body variant of Alzheimer's disease (LBV); Combined Alzheimer's and Parkinson disease (CAPD); pure autonomic failure (PAF); multiple system atrophy (MSA), such as olivopontocerebellar atrophy, striatonigral degeneration, and Shy-Drager Syndrome; pantothenate kinase-associated neurodegeneration; Down's Syndrome; Gaucher disease-related synucleinopathies; and neurodegeneration with brain iron accumulation.

Sepsis

LAG3 expression is up-regulated in sepsis (Patil et al., 2017). Accordingly, one or more of the peptides, modified peptides, or nucleic acids described above may be useful to treat sepsis, either alone or in combination with other therapeutic interventions such as antibiotics, intravenous fluids, and vasopressors.

Infectious Diseases

In some embodiments, one or more of the disclosed peptides, modified peptides, or nucleic acids described above can be administered to treat infectious diseases, including chronic infections, caused, e.g., by viruses, fungi, bacteria, and protozoa, and helminths, either alone or in combination with other therapeutic interventions.

Examples of viral agents include human immunodeficiency virus (HIV), Epstein Barr Virus (EBV), Herpes simplex (HSV, including HSV1 and HSV2), Human Papillomavirus (HPV), Varicella zoster (VSV) Cytomegalovirus (CMV), and hepatitis A, B, and C viruses.

Examples of fungal agents include Aspergillus, Candida, Coccidioides, Cryptococcus, and Histoplasma capsulatum.

Examples of bacterial agents include Streptococcal bacteria (e.g., pyogenes, agalactiae, pneumoniae), Chlamydia pneumoniae, Listeria monocytogenes, and Mycobacterium tuberculosis.

Examples of protozoa include Sarcodina (e.g., Entamoeba), Mastigophora (e.g., Giardia), Ciliophora (e.g., Balantidium), and Sporozoa (e.g., Plasmodium falciparum, Cryptosporidium).

Examples of helminths include Platyhelminths (e.g., trematodes, cestodes), Acanthocephalins, and Nematodes.

Vaccine Adjuvants

In some embodiments one or more of the disclosed peptides, modified peptides, or nucleic acids described above can be administered as a vaccine adjuvant in conjunction with a vaccine to enhance a response to vaccination (e.g., by increasing effector T cells and/or reducing T cell exhaustion). The vaccine can be, for example, an RNA vaccine (e.g., US 2016/0130345, US 2017/0182150), a DNA vaccine, a recombinant vector, a protein vaccine, or a peptide vaccine. Such vaccines can be delivered, for example, using virus-like particles, as is well known in the art.

EXAMPLE 1 Peptide Library Screening

The TriCo-20™, TriCo-16™, Ph.D.-12™, and Ph.D. C7™ Phage Display Peptide Libraries (Creative Biolabs, 45-1 Ramsey Road, Shirley, N.Y. 11967) were screened by performing several rounds of bio-panning to identify binders of soluble recombinant human LAG3.

After four rounds of screening, seven peptides showed clear enrichment for specific binders as defined by greater than 2-fold higher coated signal over uncoated signal in the clonal phage ELISA (Table 2).

TABLE 2 Clonal Phase ELISA SEQ coated uncoated ID clone signal signal peptide sequence NO: LAG3-11 0.271 0.093 SAPWEPLHWPEDWWQGTGEW 1 LAG3-42 0.378 0.084 DWNFQQWDWKKHNHLDSHVV 2 LAG3-48 0.227 0.094 FYSPNHEEYHDWNVDSSVNE 3 LAG3-51 0.234 0.076 KVWQVPQDTQHWLSPNFYSV 4 LAG3-54 0.417 0.103 ACGPGSFGDCGGG 5 LAG3-56 0.529 0.101 HIQNWSYWLNQDMMNQQVWKS 6 LAG3-60 0.330 0.091 HESGSVPHPWQFFTHYVS 7

EXAMPLE 2 Peptide Blockage of LAG3 Signaling

A cell-based reporter assay was used to assess whether binding of the seven peptides identified above was sufficient to block the interaction with LAG3 and its ligand MHC-II. The components of the assay include (1) a Jurkat T cell line that stably expresses human LAG3 and a stable NFAT-luc2P luciferase reporter, (2) a Raji cell line that expresses human MHC-II, and (3) a positive control anti-LAG3 antibody that blocks the interaction of LAG3 and MHC-II. In brief, Jurkat cells expressing LAG3 are stimulated with a T cell receptor (TCR) activator molecule, resulting in expression of luciferase. When the Jurkat cells are co-cultured with an a Raji cell line expressing the MHC-II molecule, the interaction of LAG3 on the surface of a Jurkat cell with MHC-II on the surface of a Raji cell inhibits T cell activation, leading to a reduction in luciferase expression. The addition of a neutralizing antibody against LAG3 blocks the inhibition signal and allows luciferase expression to proceed. BIO-GLO™ (Promega) was used to measure luciferase expression. The seven LAG3 peptides were tested at concentrations of 0, 0.64, 1.6, 4, 10, 25, & 100 μM.

Results of the positive control assay using the anti-LAG3 control antibody are shown in FIG. 1A. These results demonstrate that the control antibody restores luciferase expression in a dose-dependent manner, with peak-fold inhibition of approximately 5 at an antibody concentration of 25 μg/ml.

Results of the assay testing the seven LAG3 peptides identified above and a negative control peptide (SSYHHFKMPELHFGKNTFHQ; SEQ ID NO:9) are shown in FIG. 1B. These data are presented as fold increase in luciferase activity, where for each peptide the relative light units (RLUs) measured at 100 μM was compared to the RLUs measured at 0.64 μM. The results demonstrate that two of the peptides, LAG3-11 and LAG3-56, restore luciferase expression with fold inhibition of approximately 2.8 and 2.2, respectively, at a concentration of 100 μM.

EXAMPLE 3 Peptide Disruption of LAG3-MHC-II Interaction

A Homogeneous Time-resolved Fluorescence (HTRF) LAG3/MHC-II binding assay (Cisbio US Inc.) was used to measure the interaction between MHC-II and LAG3 in the presence of peptides. In this assay, the interaction between Tag1-LAG3 and Tag2-MHC-II is detected by using anti-Tag1-Terbium (HTRF donor) and anti-Tag2-XL665 (HTRF acceptor). When the donor and acceptor antibodies are brought into close proximity due to LAG3 and MHC-II binding, excitation of the donor antibody triggers fluorescent resonance energy transfer (FRET) towards the acceptor antibody, which in turn emits specifically at 665 nm. This specific signal is directly proportional to the extent of LAG3/MHC-II interaction. Thus, an agent that blocks the interaction between LAG3 and MHC-II will cause a reduction in HTRF ratio.

An anti-human LAG3 antibody (Novoprotein #GMP-A092, Lot 0331158, 500 nM) was tested in the assay at an eleven-point, serially diluted semi-log dose response curve starting at 100 nM and served as a positive control. The ovalbumin peptide was used as a negative control. Peptides were reconstituted at a concentration of 20 mM in 100 μM DMSO and tested at an eleven-point dose response curve starting at 100 μM followed by 4-fold dilutions. Each dose was tested in triplicate.

FIGS. 2A-D are graphs showing the results of four independent experiments testing peptide LAG3-11. These results demonstrate that peptide LAG3-11 disrupts the interaction of LAG3 and MHC-II.

FIGS. 3-9 are graphs showing the results of experiments testing peptides LAG3-11 (FIG. 3), LAG3-42 (FIG. 4), LAG3-48 (FIG. 5), LAG3-51 (FIG. 6), LAG3-54 (FIG. 7), LAG3-56 (FIG. 8), and LAG3-60 (FIG. 9). The individual HTRF ratios used to construct these graphs are shown in Table 3A and Table 3B.

TABLE 3A LOG LOG [Compound] [Compound] M tested M tested Anti-LAG3 Anti-LAG3 for Ab for peptide Ab plate 1 Ab plate 2 OVA peptide LAG3-11 LAG3-42 −6.30103 −4 2261 2359 2383 2234 2090 2346 8492 8909 7154 3213 3460 3458 7234 7037 7142 −6.90309 −4.60206 2647 2555 2743 2551 2501 2502 8472 8683 8449 4749 5287 5014 8389 8097 8045 −7.50515 −5.20412 2867 2915 2884 2971 2846 2840 8616 8579 9015 6812 6892 6696 8629 8765 8733 −8.10721 −5.80618 3203 3242 3170 3397 3262 3125 8833 9374 9180 7774 8164 7993 9281 8905 8572 −8.70927 −6.40824 4160 4457 4334 4286 4196 4352 8634 9280 9189 8538 8718 8858 9189 8945 8784 −9.31133 −7.0103 7218 7408 7295 7240 7263 7467 8654 8970 8380 8794 8729 8889 9432 8649 9072 −9.91339 −7.61236 8483 8643 8452 8987 8533 8601 8776 8568 9015 9090 9036 9329 9209 8787 9109 −10.5154 −8.21442 9213 8795 8849 9499 9021 8595 8624 8987 9219 9012 9293 9067 9407 8205 9247 −11.1175 −8.81648 9027 9147 8987 9102 9305 8453 8724 8639 8684 8877 8955 8992 9579 9134 8703 −11.7196 −9.41854 9013 8676 8552 9004 9330 8893 8396 8788 8625 8591 6950 8287 9137 8550 8958 −12.3216 −10.0206 8724 8742 8355 8952 8717 8824 8986 8457 8356 8212 8748 8700 8860 8937 8907 −12.9237 −10.6227 8512 9425 9136 9058 8523 8363 9086 8892 8633 8886 8842 9097 9016 8914 9210

TABLE 3B LOG LOG [Compound] [Compound] M tested M tested for Ab for peptide LAG3-48 LAG3-51 LAG3-54 LAG3-56 LAG3-60 −6.30103 −4 3507 2809 3028 3058 2773 2875 4122 3912 2283 4194 4083 4373 2986 3079 −6.90309 −4.60206 5662 5088 5724 6649 6521 6468 6709 6833 7055 6880 7058 7142 5934 5959 5991 −7.50515 −5.20412 8301 8213 8200 7908 8071 8322 8561 8512 8691 8218 8349 8414 8233 7988 7918 −8.10721 −5.80618 8663 9082 9045 8723 8946 8748 9205 9142 9156 8791 8658 8464 8525 8398 8342 −8.70927 −6.40824 9264 9194 9135 9265 8583 8662 9048 8773 9161 9040 9185 9082 8614 8929 9290 −9.31133 −7.0103 8727 9103 9142 8098 9193 9017 9141 9004 9105 8147 9275 9111 9142 8745 8892 −9.91339 −7.61236 8936 9357 9297 8762 9360 9173 9031 9075 8674 8935 9303 9093 8987 8983 9320 −10.5154 −8.21442 9082 9139 9095 8950 8608 8357 8645 8867 8996 8765 9591 9178 9275 8931 9366 −11.1175 −8.81648 8708 9153 8757 8834 8187 8957 8918 8630 8130 8856 8856 8869 9059 9248 8887 −11.7196 −9.41854 8564 8922 8442 8867 8809 8630 8930 8755 8942 9050 9029 9176 8772 8594 9169 −12.3216 −10.0206 8765 9097 8602 8784 8779 8696 9203 8748 8344 9022 8887 8540 8924 8349 8904 −12.9237 −10.6227 8663 8904 9303 9082 9104 9298 9262 8921 9100 8885 9204 8617 8795 9240 9350

EXAMPLE 5 Peptide Enhancement of CD8+ T Cell Responses

This Example demonstrates the effect of peptide LAG3-11 on the IFN-γ secretion and proliferation in a human peripheral blood mononuclear cell (PBMC)-based recall assay. PBMCs were obtained from a human donor who had previously been identified as a positive responder to Epstein-Barr virus (EBV) and Cytomegalovirus (CMV) viral-specific peptides. 5×10⁵ PBMCs in 200 μL of media were stimulated with EBV and CMV viral-specific peptides in the presence or absence of LAG3-11. Seven days post-stimulation, the percentage of virus-specific CD8+ T cells were identified via flow cytometry using MHC-I tetramers. Supernatants were also collected and the amount of IFN-γ determined via ELISA.

The results, shown in FIG. 11, demonstrate that LAG3-11 increases IFN-γ secretion by human PBMCs 3-fold relative to the viral-specific peptides alone. The ˜2-fold increase in percentage of tetramer⁺ CD8 T cells indicates that the LAG3-11 peptide may enhance T cell proliferation.

EXAMPLE 6 Interaction of Peptides with FGL1

This example demonstrates the ability of LAG-11 and LAG-56 to inhibit the interaction between human LAG3 and FGL1. The peptides were tested using a Human LAG3/FGL1 TR-FRET Binding Assay (BPS Bioscience) carried out according to the manufacturer's instructions.

Peptide stocks of LAG3-11, LAG3-42, LAG3-48, LAG3-51, LAG3-54, LAG3-56, LAG3-60 and OVA were prepared at 1 mM followed by a 1:5 dilution in plate reactions. LAG3-11 and OVA were tested at 200, 50, 13, 3, 0.8, 0.2, 0.05, and 0.01 μM. The other peptides were tested at 200, 50, 13, and 3 μM. A neutralizing anti-human LAG3 antibody (BPS Bioscience Cat. #71219) was used as a positive control.

Reaction mixes were incubated 1 hr at RT before development. After development, plate was read in a Tecan M1000 TR-FRET instrument. Percent activity was calculated as follows:

% Activity=100×[(sample−minimum)/(maximum−minimum)]

The results are shown in FIG. 11.

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1. A peptide comprising an amino acid sequence selected from the group consisting of SEQ ID NOS:1, 2, 3, 4, 5, 6, and
 7. 2. The peptide of claim 1, which consists essentially of the amino acid sequence.
 3. The peptide of claim 2, which consists of the amino acid sequence.
 4. A nucleic acid encoding the peptide of claim
 1. 5. The nucleic acid of claim 4, which is an expression construct.
 6. The nucleic acid of claim 5, which is present in a CAR-T cell or an oncolytic virus.
 7. The nucleic acid of claim 4, wherein the nucleic acid is selected from the group consisting of DNA, cDNA, PNA, and RNA.
 8. A host cell comprising the nucleic acid of claim
 4. 9. A peptide composition consisting essentially of one or more peptides of claim
 1. 10. A pharmaceutical composition comprising: (a) an active agent selected from the group consisting of: (i) a peptide of claim 1; (ii) a nucleic acid encoding the peptide; (iii) a CAR-T cell expressing the peptide; and (iv) an oncolytic virus expressing the peptide; and (b) a pharmaceutically acceptable carrier.
 11. The pharmaceutical composition of claim 10, wherein the active agent is the nucleic acid, wherein the nucleic acid is selected from the group consisting of DNA, cDNA, PNA, and RNA.
 12. The pharmaceutical composition of claim 10, wherein the nucleic acid is RNA.
 13. The pharmaceutical composition of claim 12, wherein the RNA comprises a modification selected from the group consisting of (i) modification of a ribose sugar, (ii) modification of a phosphate linkage, and (iii) modification of a base.
 14. The pharmaceutical composition of claim 13, wherein the modification is selected from the group consisting of a ribo-difluorotoluyl nucleotide, a 4′-thio modified RNA, a boranophosphate linkage, a phosphorothioate linkage, a 2′-O-methyl (2′-OMe) sugar substitution, a 2′-fluoro (2′-F), a 2′-O-methoxyethyl (2′-MOE) sugar substitution, a locked nucleic acid (LNA), and an L-RNA.
 15. The pharmaceutical composition of claim 10, wherein the active agent is the peptide, wherein the peptide is provided with a peptide carrier system selected from the group consisting of a microparticle, a polymeric nanoparticle, a liposome, a solid lipid nanoparticle, a hydrophilic mucoadhesive polymer, a thiolated polymer, a polymer matrix, a nanoemulsion, and a hydrogel.
 16. A method of inhibiting the progression of a hyperproliferative disorder, inhibiting the progression of a synucleinopathy, inhibiting the progression of sepsis, inhibiting the progression of an infectious disease, or enhancing a response to a vaccine, comprising administering to an individual in need thereof an effective amount of the pharmaceutical composition of claim
 10. 17. The method of claim 16, wherein the pharmaceutical composition is administered to inhibit progression of the hyperproliferative disorder.
 18. The method of claim 17, wherein the hyperproliferative disorder is a cancer.
 19. The method of claim 18, wherein the cancer is a melanoma.
 20. The method of claim 19, wherein the second therapy is selected from the group consisting of: (i) a cancer vaccine; (ii) a chimeric antigen receptor (CAR) T cell therapy; (iii) a therapy that comprises reducing or blocking activity of a molecule selected from the group consisting of PD-1, PD-L1, lymphocyte-activation gene-3 (LAG3), cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), V-domain Immunoglobulin Suppressor of T cell Activation (VISTA), T-cell Immunoglobulin domain and Mucin domain 3 (TIM-3), a killer immunoglobulin-like receptor (KIR), indoleamine (2,3)-dioxygenase (IDO), B and T Lymphocyte Attenuator (BTLA), A2A adenosine receptor (A2AR); (iv) a cytokine; (v) an agonist of a molecule selected from the group consisting of CD40, OX40, glucocorticoid-induced tumor necrosis factor-related protein (GITR), and Inducible T-cell COStimulator (ICOS); (vi) an oncolytic virus; and (vii) a therapeutic agent selected from the group consisting of a 4-1BB agonist, a 4-1BB antagonist, an inhibitor of anaplastic lymphoma kinase (ALK), an inhibitor of histone deacetylase (HDAC), and an inhibitor of VEGFR.
 21. The method of claim 16, wherein the pharmaceutical composition is administered to inhibit the progression of a synucleinopathy.
 22. The method of claim 21, wherein the synucleinopathy is selected from the group consisting of Parkinson's disease (PD), dementia with Lewy bodies (DLB), pure autonomic failure (PAF), and multiple system atrophy (MSA).
 23. The method of claim 16, wherein the pharmaceutical composition is administered to inhibit the progression of sepsis.
 24. The method of claim 16, wherein the pharmaceutical composition is administered to inhibit the progression of an infectious disease.
 25. The method of claim 16, wherein the pharmaceutical composition is administered to enhance a response to a vaccine. 